SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '933c1017fe43cad962c5b91f32c097f1bfae3f575034857c8f20ef7372bb1fcb' 
  AND token = 'V2tNwUl8T0V859So1VzkupiA17BoszB0nYTuTBVn7Ok=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}